Why not go big?

Get greedy and someone will be out for you

The reason is simple.

You're basically handed a non-lethal version of **** Note. The book, introduced in a manga by the same name, allows the owner to kill anyone whose name is written in it, provided the writer also has the person's face in mind. The owner, Light, used the notebook to try and create a crime-free world, becoming a vigilante known as "Kira," which sparks a complex conflict with a brilliant detective named L who seeks to stop him.

That is an interesting concept, but the manga was written in 2006, before the widespread of Internet and the author and many people has yet to understand how it can be used.

Just in 10 years, in 2016, a group of 4chan users, collaborated to determine a location of a terrorist training camp in Syria by examining details on photographs published by the terrorist geoup, and caused an airstrike to be called on it.

Get everyone topless, and a parent may notice the difference between your school and other schools across the district. Make it a district rule and people will compared it with other districts. Nationwide? Still not safe as someone may notice when the transition happens, since the would be countless video recording showing people wearing clothes one second, and topless in another. And the list goes on.

That's nothing compared to something big like asking for a world peace. Having secret service agencies trying to locate the person who impose the world rule on everyone will keep you up all night.

Also, whenever there's a rule, there's bound to be a rule breaker.

No. Being cautious is the best approach, and for someone smart like you, it would be fun to figure out things to do on a small scale without being detected.

Something like you have a porn star as a girlfriend or stepmother could be considered as a small scale. Or something else on your mind?